C++ Library - <regex>



Introduction

It is a standardized way to express patterns to be matched against sequences of characters. some of typical regex parameters are as shown below −

  • Target sequence (subject) − It is used to searched for the sequence pattern.

  • Regular expression (pattern) − It is used to searched for in the target sequence.

  • Matches array − Matches information is stored in one of the special match_results array types (such as cmatch or smatch).

  • Replacement strin − This operation replaces the matches.

Regex operations

Iterator types

basic_regex instantiations

Sr.No. Instantiation & description
1 regex

It is a regex class.

2 wregex

It is a wregex class.

match_results instantiations

Sr.No. match_results instantiation & description
1 cmatch

These are match_results for string literals.

2 wcmatch

These are match_results for wide string literals.

3 smatch

These are match_results for string objects.

4 wsmatch

These are match_results for wide string objects.

sub_match instantiations

Sr.No. sub_match instantiation & description
1 csub_match

It is a sub_match for string literals.

2 wcsub_match

It is a sub_match for wide string literals.

3 ssub_match

It is a sub_match for strings.

4 wssub_match

It is a sub_match for wide strings.

Namespaces